Independent evolutionary history between the Balkan ranges and more northerly mountains in Campanula alpina s.l. (Campanulaceae): Genetic divergence and morphological segregation of taxa

Abstract

Although the Balkan Peninsula belongs to the main European biodiversity centres, phylogeographical structure of its high‐mountain flora and relationships with adjoining mountain systems remain almost unknown. Here, we analyse the evolutionary patterns in Campanula alpina s.l., which comprises C. alpina Jacq. (eastern Alps, Carpathians) and the mostly neglected, allopatric Balkan taxon C. orbelica Pančić. Using a range‐wide sampling, two molecular marker systems (mostly nuclear AFLPs and chloroplast DNA sequences), flow cytometry and morphometric assessment, we (1) test earlier hypotheses assuming the impact of the Balkan lineages on the history of populations in the Alps and the Carpathians; (2) elucidate the long‐lasting controversy concerning the taxonomic status of the populations in the Balkan Peninsula. The primary evolutionary break, evidenced by a substantial genetic differentiation, separated the Alpine/Carpathian and Balkan populations. Thus, the previously hypothesized influence of the Balkan gene pool on the present more northerly lineages (especially on a distinct phylogeographical group occurring in the southwestern Carpathians) was rejected. Bayesian phylogenetic analysis of cpDNA may support the Carpathians as the ancestral area within C. alpina from which the species reached the Alps, although strongly divergent AFLPs point at a relatively ancient time of this colonization. Molecular data and clear morphological segregation supported C. orbelica as a Balkan endemic species evolutionarily divergent from C. alpina. Both taxa are lectotypified, illustrated and morphologically characterized; their diagnostic characters are outlined.

Biogeography of the Carpathians: evolutionary and spatial facets of biodiversity

“…Populations from these two areas often share closely‐related genetic lineages (Ronikier et al ., ; Drag et al ., ; György et al ., ) and such affinities have been documented even for microbial communities in high‐mountain grasslands (Geremia et al ., ). Nevertheless, numerous cases of genetic divergence suggesting long‐term isolation of West Carpathians and Eastern Alps populations, often pre‐dating the last glaciation, have also been documented (Dzialuk et al ., ; Homburg et al ., ; Ronikier & Zalewska‐Gałosz, ; Pachschwöll et al ., ; Drees et al ., ; Frajman, Graniszewska & Schönswetter, ). It is difficult to correlate these divergent histories with features such as different dispersal potential of the taxa and they probably reflect individual histories of the species.…”

“…). This was substantiated in a later analysis of the same species, which showed that plastid DNA haplotypes from this area may constitute the most divergent intraspecific lineage (Ronikier & Zalewska‐Gałosz, ). The evolutionary importance of the south‐western edge of the Carpathians was recently supported by the phylogeographical structure of the montane plant Onobrychis transylvanica (Fabaceae; Băcilă et al ., ).…”

“…Other studies also confirm the historical links between the two areas and confirm the importance of complex episodes of isolation and expansion (Kuzmanović et al ., ). Finally, in some cases, populations in the Carpathians and the Balkan Peninsula formed allopatric groups that underwent long‐term isolation and eventual speciation (Ronikier & Zalewska‐Gałosz, ). Thus, intraspecific phylogeographical patters in this area, just as in the case of the Carpathians–Alps zone, were diverse and no single biogeographical model can explain these historical processes.…”

A morphometric study and taxonomic revision of Fritillaria tubaeformis complex (Liliaceae)

“…A further data set consisting of twenty-seven variant characters was prepared combining selected in vivo and herbarium characters and Pearson correlation coefficients (parametric) computed among all their pairs in order to check if any strong correlation (r0.80; p<0.01) existed that could potentially affect the results of further analyses (Dobeš et al 2013;Ronikier and Zalewska-Gałosz 2014). For not normally distributed variables, a Spearman correlation non-parametric method was applied (Šingliarová et al 2011).…”

Genetic diversity and morphological variability in the Balkan endemicCampanula secundiflora s.l.(Campanulaceae)

“…In addition, some neglected or cryptic taxa have been reaffirmed: C. cichoracea Smith (Škondrić et al ., ); C. comosiformis (Hayek & Janch.) Frajman & Schneeweiss (Frajman & Schneeweiss, ); and C. orbelica Pančić (Ronikier & Zalewska‐Gałosz, ). Thus, it appears that the taxonomy of this genus has still not been explored satisfactorily and we expect an even greater number of taxa to be present in the Balkan Peninsula.…”